From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752349AbVHGQ54 (ORCPT ); Sun, 7 Aug 2005 12:57:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752352AbVHGQ54 (ORCPT ); Sun, 7 Aug 2005 12:57:56 -0400 Received: from e35.co.us.ibm.com ([32.97.110.133]:49608 "EHLO e35.co.us.ibm.com") by vger.kernel.org with ESMTP id S1752348AbVHGQ54 (ORCPT ); Sun, 7 Aug 2005 12:57:56 -0400 Date: Sun, 7 Aug 2005 22:28:33 +0530 From: Srivatsa Vaddagiri To: Con Kolivas Cc: Adrian Bunk , linux-kernel@vger.kernel.org, ck@vds.kolivas.org, tony@atomide.com, tuukka.tikkanen@elektrobit.com, george@mvista.com, Andrew Morton Subject: Re: [PATCH] i386 No-Idle-Hz aka Dynamic-Ticks 5 Message-ID: <20050807165833.GA13918@in.ibm.com> Reply-To: vatsa@in.ibm.com References: <200508031559.24704.kernel@kolivas.org> <200508060239.41646.kernel@kolivas.org> <20050806174739.GU4029@stusta.de> <200508071512.22668.kernel@kolivas.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200508071512.22668.kernel@kolivas.org> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Aug 07, 2005 at 03:12:21PM +1000, Con Kolivas wrote: > Respin of the dynamic ticks patch for i386 by Tony Lindgen and Tuukka Tikkanen > with further code cleanups. Are were there yet? Con, I am afraid until SMP correctness is resolved, then this is not in a position to go in (unless you want to enable it only for UP, which I think should not be our target). I am working on making this work correctly on SMP systems. Hopefully I will post a patch soon. Another observation I have made regarding dynamic tick patch is that PIT is being reprogrammed whenever the CPUs are coming out of sleep state (because of an interrupt say). This can happen at any arbitary time, not necessarily on jiffy boundaries. As a result, there will be an offset between when jiffy interrupts will now occur vs when they would have originally occured had PIT never been stopped. Not sure if having this offset is good, but atleast one necessary change that I foresee if zeroing delay_at_last_interrupt when disabling dynamic tick. For that matter, it may be easier to disable the PIT timer by just masking PIT interrupts (instead of changing its mode). Will keep you posted of my progress with dynamic tick patch. -- Thanks and Regards, Srivatsa Vaddagiri, Linux Technology Center, IBM Software Labs, Bangalore, INDIA - 560017